By Elizabeth Howcroft LONDON, April 19 (Reuters) - What do you do with a $69 million artwork that doesn't physically exist? That's the question faced by the Singapore-based investor calling himself Metakovan, who made headlines last month when he bought the digital artwork "Everydays: The First 5000 Days" by the American artist Beeple at Christie's. The work is a non-fungible token (NFT) - a new type of virtual asset that has its ownership status and authenticity verified by blockchain.

NFTs have exploded in popularity in 2021, with prices skyrocketing. Metakovan, real name Vignesh Sundaresan, plans to put the artwork on display in four virtual world environments. He is working with architects to design gallery complexes that the public can enter via web browsers or virtual reality technology. But art is just one part of a new economy of blockchain-based virtual worlds where land, buildings, avatars and even names can be bought and sold as NFTs, often fetching hundreds of thousands of dollars.

In these environments, referred to as the metaverse, people can wander around with friends, visit virtual buildings and attend virtual events. Metakovan's plans are an ambitious undertaking, but he says he is the world's biggest NFT investor. His collection of NFTs and other crypto assets, the Metapurse fund, is valued at $189 million, according to NonFungible.com, a site that aggregates sales history data from NFT marketplaces. "The current Cambrian explosion of NFTs that you see is all about acquisition - people want to buy up NFTs, gobble as many of them as they can," said Anand Venkateswaran, aka Twobadour, who runs the Metapurse fund with Metakovan. "But it's just the tip of the iceberg.

The real explosion will happen when they're able to ... experience these NFTs as they were intended. If it's a plot of virtual land, you ought to move around in it, have an immersive experience in it." In what will be one of the biggest names to join the party, videogame maker Atari told Reuters it planned to launch its own blockchain-based virtual world and would soon announce details. Online environments are going to be "very very big", regardless of fluctuations in the price of bitcoin, said Frederic Chesnais, head of Atari's blockchain division and the company's former CEO.

NFT real estate could one day fetch millions of dollars, he added. Investors caution, however, tradersleader binary options that while big money is flowing into NFTs, the market could represent a price bubble, with the risk of major losses if the hype dies down. There could also be prime opportunities for fraudsters in a market where many participants operate under pseudonyms. A PLOT OF VIRTUAL LAND: $500K+ The NFT frenzy has heightened interest in blockchain-based online environments.

The best known are Decentraland, Cryptovoxels, Somnium Space and The Sandbox, where virtual real estate prices are hitting new highs. Decentraland has seen more than $50 million in total sales, including land, avatars, usernames and wearables like virtual outfits. A patch of land measuring 41,216 virtual square metres sold for $572,000 on April 11, which the platform said was a record. Another Decentraland plot sold for $283,567 on March 21, according to NonFungible.